Drug could transform lives of those who are unable to exercising because of obesity or serious physical disability, mouse study suggests
For those who cannot exercise, it could be the answer: rather than spending hours in the gym, the added benefit of fitness develop could be delivered in a tablet.
The prospect of an exercise pill might be music to the ears of couch potato, long-distance truck driver and stressed-out office workers, but researchers believe it could transform the lives of people who are unable to workout because of obesity or serious physical disabilities.
Hopes for such a pill emerged on Tuesday from scientists who found that an experimental narcotic let mice to run on a treadmill for 270 minutes before exhaustion set in. Mice that ran without the medication lasted only 160 minutes before reaching their physical limit.
The endurance boost is complemented by other apparent health benefits, scientists detected, leading mice who had the narcotic for eight weeks to put on less weight and better control their blood sugar levels, suggesting a pill might also help people with diabetes.
Scientists led by Ronald Evans at the Salk Institute in San Diego made the discovery after they set out to explore what endurance meant on the molecular level. If we really understand the social sciences, can we replace training with a drug? he said.
They turned to a drug known as GW501516 which had previously been shown to improve staman and burn fat faster. Through a series of tests with mice on treadmills, Evans found that the medication changed the activity of nearly 1000 genes. Many of the genes that became more active were involved in the breakdown and burning of fat. But other genes were inhibited, including some that convert sugar into energy.
Writing in the publication Cell Metabolism, the scientists describe how the findings might explain why runners, cyclists and others athletes can hit the wall when they push themselves hard. The drug stimulates the body burn fat faster, but also burn sugar more slowly. The upshot is that, on the narcotic, the drop in blood sugar level that is responsible for the feeling of making the wall happens much later than normal.
In endurance sport rivalries, such as cycling, marathon operates, race walk-to and cross-country skiing, making the wall is a dramatic demonstration of sudden and complete exhaustion, the scientists write. But the narcotic, which achieves its effects through muscle proteins called PPARD, is sufficient to dramatically improve endurance capacity.
Exercise activates PPARD, but were showing that you can do the same thing without mechanical develop. It means you can improve endurance to the equivalent level as somebody in train, without all of the physical effort, said Weiwei Fan, the papers first author.
The compound was originally developed by what is today GlaxoSmithKline and a US company called Ligand pharmaceuticals in the 1990 s. Intended to treat metabolic and cardiovascular disease, it was later abandoned, apparently after a number of studies found that high doses might cause cancer.
But despite the drug being dropped commercially, scientists continue to study the compound. A decade ago, exams in animals showed that it could potentially boost staman. The finding spawned a black market for the narcotic, and its subsequent abuse by some athletes in the 2008 Beijing Olympics. The following year, the World Anti-Doping Agency banned the drug and warned that it was not safe.
Ali Tavassoli, professor of chemical biology at Southampton University who was not involved in the latest examine, said that any workout pill that scientists develop could potentially be abused , not only by athletes, but by horse trainers and others.
But there are groups of people who for one reason or other cannot exercise, people with real problems, and you could potentially have a pill that gives them some of the benefits of exert, he told. A pill of this sort might allow them to a place where they can start to exercise for real.
Tavassoli is not remain convinced that an exercise pill will arrive any time soon though. Personally, I am not certain that such a pill would be possible. Theres a big difference between showing in an organism that you are able to simulated exercising over the short-term and demonstrating the long-term effects of doing this.
Someone with obesity or diabetes might be taking a pill for 40 or 50 years. What happens when you take a drug like this for that long? What happens to you? These are big unanswered questions, Tavassoli said. I cant see these things get regulatory approval.
Louise MacKenzie, a pharmacologist at the University of Hertfordshire, who has studied GW501516, said it was once considered a wonder drug because of its potential to treat a number of medical conditions. But while the compound appears to have benefits at low doses, it can have bad side effects at high doses. It goes from being remarkably healthy to being the complete opposite, theres no in-between, she told. Nevertheless, MacKenzie said the narcotic was a good starting block for scientists hoping to find new ways to treat patients. I can definitely assure a future where the problems are solved. You simply need to have enough clever scientists working on them, she said.
Read more: www.theguardian.com